FINESSE – Fiber optic sensing systems

Coordinating university or institute

RISE Research Institutes of Sweden,



Project description

FINESSE is a collaborative research and training network, gathering 26 European universities, research centers and industrial partners with complementary expertise in distributed optical fibre sensor systems for a safer society.

One activity within FINESSE involved evaluating the use of fibre optic sensors for monitoring in harsh radiative environment. Indeed, any sensor to be installed in a silicon detector at CERN’s LHC should ideally fulfil the requirements of being radiation resistant and insensitive to magnetic fields, while having small dimensions, reliable reading across long distances, and ease of multiplexing to form large network of sensors. Thanks to their inherent properties, fibre optics sensors have been identified as candidates to monitor relative humidity inside the detector enclosure. In this work, humidity measurement was performed every 70 cm over a single 1 km fibre using phase-sensitive Optical Time Domain Reflectometry, an advanced fibre optic sensing technique.




RISE, Research Institutes of Sweden

  • Kenny Hey Tow, Researcher, Fibre optic unit
  • Åsa Claesson, Researcher, Fibre optic unit

Core deliverables

The optical fibers used in the study were developed and produced by RISE Fiberlab. These fibers, and the sensors built from them, were evaluated for distributed relative humidity sensing in terms of response time and sensitivity.

Total budget

In kind


  • EPFL, Swiss Federal Institute of Technology


210525 Finesse Rise Bild Specialty Optical Fiber

Procurement codes

Optics and photonics

Last edited